There are still a few things that are not really meant (or allowed) to be leagally redistributed. However, if you dig into it more, you can unpack the existing ISO, and use the customize process to add to it, and possibly remove some things if you want, and then (as said), recreate the g4dos menue structure to be what you want, then rebuild the ISO.

The only winbuilder scripts that use HBCD are meant to add it to an existing project, and they strip out some of the less desireable bits...

I have been doing this for a some time. Because I did not know how to make my own boot cd
But its not legal, depending on your country i think.
I and some people who I work with use HBCD almost every day. Because it has alot of tools in one place.
Its not that hard. Just 7zip tools and create the batch file.